Method for manufacturing original master

ABSTRACT

An original master manufacturing method of rotating an original master at a constant linear velocity, moving in a plane the original master in a predetermined radial direction at a constant velocity which is provided with a predetermined amount of movement per round of the original master, deflecting the electron beam in the planar movement direction of the original master by a first deflection amount equal to the predetermined movement amount per round of the original master on the surface of the original master during exposure of the concentric circular data patterns corresponding to first through (n−1)-th rounds of each of the plurality of tracks, upon completion of the exposure of the concentric circular data patterns corresponding to the first through (n-1)-th rounds, deflecting the electron beam in a direction opposite to the planar movement direction of the original master by a second deflection amount equal to the predetermined distance on the surface of the original master, and upon completion of exposure of the concentric circular data pattern corresponding to an n-th round of each of the plurality of tracks, deflecting the electron beam in the direction opposite to the planar movement direction of the original master by a third deflection amount on the surface of the original master such that an irradiation position of the electron beam is located at an exposure start position on the concentric circle of a first round of an adjacent track.

TECHNICAL FIELD

The present invention relates to a method for manufacturing an originalmaster having a plurality of tracks formed thereon by irradiating anelectron beam onto the original master having a resist layer on asurface thereof to expose the resist layer.

BACKGROUND ART

In a conventional process for drawing trains of pits onto concentriccircular tracks by irradiating a laser beam onto an original master foroptical disks to subject the original master to expose, in the course ofone revolution of the original master, a stage that carries the originalmaster is moved in the radial direction of the original master while thebeam is deflected in the same direction as the direction of the movementat a uniform rate by the equivalent of the track pitch (see JapanesePatent Application Laid-open Publication No. S63-112839). For example,when pit trains are drawn onto a plurality of tracks through exposure,which is started by irradiating a beam from a starting point A of thefirst track as shown by arrows in FIG. 1A, by the time that the beamirradiation position reaches the starting point A again by onerevolution of the original master, the beam is deflected at a constantrate by a distance of the track pitch as shown in FIG. 1B. The distanceof the track pitch corresponds to the movement distance of the stage inthe course of one revolution. When the irradiation position of the beamreaches the starting point A, the irradiation position of the beam isimmediately shifted through high-speed deflection to a starting point Bof the second track positioned in the same radial direction as thestarting point A. This beam deflection operation is repeated for eachtrack.

In a magnetic disk such as a hard disk, a concentric circular patternequivalent to that on optical disks is drawn by an electron beam, inorder to record servo patterns indicating position information.

DISCLOSURE OF THE INVENTION

However, in the magnetic disk, it is necessary to expose patterns havinghigher degrees of resolution and accuracy for higher densities. Further,since conventional original master manufacturing methods are susceptibleto the effects of electron beam stability, there are problems withdegradation such as variability of line width and variability ofirradiation position.

These are examples of the problems to be solved by the invention and itis an object of the invention to provide an original mastermanufacturing method capable of exposing concentric circular tracks ofhigh resolution and high accuracy patterns, and a computer-readableprogram for implementing the method.

An original master manufacturing method of the invention in claim 1 is amethod of irradiating an electron beam on an original master having aresist layer on a surface to expose a concentric circular data patternby n (n is an integer that is equal to or greater than 2) rounds pertrack at a predetermined distance, so that a plurality of tracks havinga predetermined track pitch are formed on the original master, themethod comprising: a rotation driving step of rotary-driving theoriginal master at a constant linear velocity; a movement step of movingin a plane the original master in a predetermined radial direction at aconstant velocity which is provided with a predetermined amount ofmovement per round of the original master; a first deflection step ofdeflecting the electron beam in the planar movement direction of theoriginal master by a first deflection amount equal to the predeterminedmovement amount per round of the original master on the surface of theoriginal master during exposure of the concentric circular data patternscorresponding to first through (n−1)-th rounds of each of the pluralityof tracks; a second deflection step of deflecting the electron beam in adirection opposite to the planar movement direction of the originalmaster by a second deflection amount equal to the predetermined distanceon the surface of the original master, upon completion of the exposureof the concentric circular data patterns corresponding to the firstthrough (n−1)-th rounds; and a third deflection step of deflecting theelectron beam in the direction opposite to the planar movement directionof the original master by a third deflection amount on the surface ofthe original master such that an irradiation position of the electronbeam is located at an exposure start position on the concentric circleof a first round of an adjacent track, upon completion of exposure ofthe concentric circular data pattern corresponding to an n-th round ofeach of the plurality of tracks.

A program of the invention in claim 7 is a program for executing anoriginal master manufacturing method of irradiating an electron beam onan original master having a resist layer on a surface to expose aconcentric circular data pattern by n (n is an integer that is equal toor greater than 2) rounds per track at a predetermined distance, so thata plurality of tracks having a predetermined track pitch are formed onthe original master, comprising: a rotation driving step ofrotary-driving the original master at a constant linear velocity; amovement step of moving in a plane the original master in apredetermined radial direction at a constant velocity which is providedwith a predetermined amount of movement per round of the originalmaster; a first deflection step of deflecting the electron beam in theplanar movement direction of the original master by a first deflectionamount equal to the predetermined movement amount per round of theoriginal master on the surface of the original master during exposure ofthe concentric circular data patterns corresponding to first through(n−1)-th rounds of each of the plurality of tracks; a second deflectionstep of deflecting the electron beam in a direction opposite to theplanar movement direction of the original master by a second deflectionamount equal to the predetermined distance on the surface of theoriginal master, upon completion of the exposure of the concentriccircular data patterns corresponding to the first through (n−1)-throunds; and a third deflection step of deflecting the electron beam inthe direction opposite to the planar movement direction of the originalmaster by a third deflection amount on the surface of the originalmaster such that an irradiation position of the electron beam is locatedat an exposure start position on the concentric circle of a first roundof an adjacent track, upon completion of exposure of the concentriccircular data pattern corresponding to an n-th round of each of theplurality of tracks.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrams showing a conventional original mastermanufacturing method;

FIG. 2 is a diagram showing a configuration of an electron beamlithography system to which an original master manufacturing method ofthe present invention is applied;

FIG. 3 is a diagram showing an exposure procedure when forming one trackthrough drawing of four concentric circles by the system of FIG. 2;

FIG. 4 is a flowchart showing operation of a main controller in thesystem of FIG. 2;

FIGS. 5A and 5B are diagrams showing a spot position and a deflectionamount of an electron beam when forming one track through drawing offour concentric circles;

FIG. 6 is a diagram showing a deflection state of the electron beam whenfour concentric circles are drawn to form one track;

FIG. 7 is a diagram showing a lithography procedure when the system ofFIG. 2 is used to form one track through drawing of n concentriccircles; and

FIGS. 8A and 8B are diagrams showing a spot position and a deflectionamount of the electron beam when n concentric circles are drawn to formone track.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the original master manufacturing method of the presentinvention of the first aspect and the program of the present inventionof the seventh aspect, in the course of exposing a plurality ofconcentric circular data patterns to form a single track, the degree towhich the electron beam is moved during exposure of the individualconcentric circular data patterns can be kept to a lower level than thatof movement of the master in a predetermined radial direction during asingle revolution, whereby it will be possible for drawing to beperformed within a short time, as well as making it possible to exposedata pattern tracks with high resolution and high accuracy throughutilization of a multiple exposure averaging effect.

Embodiments

Embodiments of the present invention will be described in detail belowwith reference to the accompanying drawings.

FIG. 2 shows an electron beam lithography system which is applied in amaster exposure process of a stamper or exposure mask for producingmagnetic disk substrates. The electron beam lithography system comprisesan electron column 1, a vacuum chamber 2, and a recording control system30 through 38.

The electron column 1 is a column-shaped component in which an electronoptical system for irradiating an electron beam onto an original master4, discussed later, inside the vacuum chamber 2 is provided. The opticalsystem inside the electron column 1 is provided with an electron emitter11, a condenser lens 12, a blanking plate 13, an aperture plate 14, adeflecting coil 15, an alignment coil 16, a high-speed deflector 17, afocus lens 18, and an objective lens 19. These components 11 to 19 arearranged within the electron column 1, in order from the top.

The electron emitter 11 generates an electron beam when a high voltageis applied thereto by an accelerating high voltage power supply 30,discussed later. The condenser lens 12 focuses the electron beamgenerated by the electron emitter 11 to produce a crossover in thecenter part of the blanking plate 13. The blanking plate 13 is composed,for example, of electrodes of an electrostatic deflection type adaptedto turn on and off the electron beam in response to an output signal ofa beam modulator 31, discussed later. The aperture plate 14 is providedwith a circular aperture for limiting the electron flux of the electronbeam. The deflecting coil 15 changes the traveling direction of theelectron beam in response to an output signal from a deflecting circuit,not shown. The alignment coil 16 deflects the electron beam in responseto an output signal of a beam position corrector 32. The high-speeddeflector 17 deflects the electron beam in a desired direction inresponse to an output signal of a deflection controller 37. The focuslens 18 performs focus control of the electron beam in response to anoutput signal of a focus controller 33, and focuses the electron beamonto the master 4 via the objective lens 19.

Within the vacuum chamber 2 there are disposed a height sensor 21, aspindle motor 22, a mirror 23, a turntable 24, a stage 25, and a stagemovement mechanism 26. The spindle motor 22 and the mirror 23 arearranged on the stage 25. The spindle motor 22 rotates the turntable 24.The original master 4 is set on the turntable 24. The master 4 may becomposed of an electron beam resist layer formed on a substrate ofsilicon, for example. The stage 25 is capable of being moved in the diskradial direction (X direction) of the original master 4 by the stagemovement mechanism 26. With a motor 27 installed as a power sourceoutside of the vacuum chamber 2, the stage movement mechanism 26performs the movement of the stage 25. The mirror 23 is provided for thepurpose of measuring a movement distance of the stage 25 in the diskradial direction. The height sensor 21 is disposed in the upper partinside the vacuum chamber 2 and is adapted to optically sense the heightof a recording position of the original master 4.

The recording control system includes the accelerating high voltagepower supply 30, the beam modulator 31, the beam position corrector 32,the focus controller 33, a position controller 34, a laserinterferometer 35, a rotation controller 36, the deflection controller37, and a main controller 38.

The accelerating high voltage power supply 30 applies a high voltage tothe electron emitter 11 in response to a command from the maincontroller 38.

The beam modulator 31 supplies a beam modulating signal to the blankingplate 13 in accordance with recording data supplied by the maincontroller 38.

The focus controller 33 moves the focal position of the beam by thefocal lens 18 in response to the recording location height informationdetected by the height sensor 21.

The laser interferometer 35 irradiates a laser beam to the mirror 23,receives the reflected light of the laser beam, and senses the locationof the mirror 23, i.e. movement distance information r relating to thestage 25. The movement distance information r indicates a recordinglocation in the radial direction of the original master 4. The movementdistance information r measured by the laser interferometer 35 issupplied to the position controller 34. The position controller 34 thencompares the movement distance information r with reference distanceinformation REF, and in response to a position error signal of thecomparison result, drives the motor 27 via motor actuating means, notshown. The position error signal is also supplied to the beam positioncorrector 32. In response to the position error signal from the positioncontroller 34, the beam position corrector 32 excites the alignment coil16, thereby deflecting the electron beam.

The rotation controller 36 drives rotation of the spindle motor 22 inresponse to a command from the main controller 38. The deflectioncontroller 37 controls deflection of the electron beam by the high speeddeflector 17 in response to a command provided by the main controller38.

The accelerating high voltage power supply 30, the beam modulator 31,the focus controller 33, a position controller 34, the rotationcontroller 36, and the deflection controller 37 are each controlled inresponse to commands of the main controller 38. The main controller 38may be composed, for example, of a microcomputer, and executes commandoperations in accordance with a program.

A pattern lithography process carried out by exposure of the originalmaster 4 using the electron beam lithography system having the aboveconfiguration will be described. The pattern lithography processinvolves forming a plurality of tracks at a track pitch 8δx. Each of theplurality of tracks is produced through drawing of four concentriccircles. The pitch of the four concentric circles is δx, and width ofthe track is 4δx.

To record servo zone data and data zone data, the main controller 38instructs the position controller 34 to set a stage movement to theaforementioned reference distance information REF, and instructs therotation controller 36 to rotate the spindle motor 22 at a constantrotational linear velocity.

The position controller 34 compares the reference distance informationREF with the movement distance information r of the stage 25 output bythe laser interferometer 25, and in response to a position error signalof the comparison result, drives the motor 27 via motor actuating means,not shown.

Through these commands and operations, the master 4 is rotated by onerotation along with the turntable 24 by the spindle motor 22, and at thesame time is moved in the master radial direction along with the stage25 by the stage movement mechanism 26. The movement distance of thestage 25 is 2δx per one rotation of the spindle motor 22. 2δx is adistance equivalent to ¼ the track pitch 8δx.

The feed velocity v of the stage 25 is expressed as:

v=(V/2πR)×2δx=Vδx/πR

where V denotes the recording linear velocity and R denotes the radiusof the recording location. The main controller 38 changes the referencedistance information REF supplied to the position controller 34 inaccordance with the feed velocity v. Since the position controller 34drives the motor 27 while generating a position error signal so as to beequal the movement distance information r and the reference distanceinformation REF to each other. As a result, the stage 25 moves at aconstant rate of 2δx per one rotation of the spindle motor 22.

The main controller 38 also instructs the accelerating high voltagepower supply 30 to apply voltage to the high voltage electron emitter11. Thus, an electron beam is generated from the electron emitter 11.Further, The main controller 38 instructs the focus controller 33 tofocus the electron beam onto the master 4.

The beam position corrector 32 excites the alignment coil 16 in responseto the position error signal from the position controller 34, therebydeflecting the electron beam.

Recording data is supplied at a fixed clock timing from the maincontroller 38 to the beam modulator 31. The clock timing is in sync withthe commands issued to the position controller 34 and the rotationcontroller 36. The recording data is data indicating servo zone data anddata zone data per disk in the order of data recorded. In response tothe recording data, the beam modulator 31 generates a modulating signal,and in response to the modulating signal the blanking plate 13 deflectsthe electron beam generated from the electron emitter 11. Thus, one ofthe case that the electron beam passes through the aperture of theaperture plate 14 and the other case that the beam does not pass throughthe aperture is obtained. In the former case, after having passedthrough the aperture the electron beam is irradiated as a spot onto arecording surface of the master 4 via the deflecting coil 15, thealignment coil 16, the high-speed deflector 17, the focus lens 18, andthe objective lens 19. In the latter case, the electron beam does nottravel beyond the aperture plate 14 and is not irradiated onto themaster 14.

A pattern in the form of a latent image is formed in sections of themaster 4 that are irradiated by the electron beam, and the resist layerin the latent image sections is removed in a subsequent developing step.The sections in which the resist layer has been removed is recessed,forming the actual pattern.

In order to form one track for recording data, data of the one trackcorresponding to one round of the disk is generated repeatedly fourtimes.

As shown in FIG. 3, when one track is drawn, points situated along thesame disk radial direction serving as a reference location on the firsttrack is designated as A, B, C, and D. The points A, B, C, and D arelocated in the alphabetical order from the inside peripheral side, atintervals of δx. The point A is a recording start point of the firsttrack, and the point D is a recording end point of the first track. Therotation controller 36 drives the spindle motor 22 so as to spin atconstant rotational linear velocity. As shown in FIG. 4, to write onetrack the main controller 38 first determines whether the recordinglocation of the spot (the exposure location) is the location of thepoint A (Step S1). Movement of the recording location to the point A isaccomplished through movement of the stage 25. If the recording locationis the location of the point A, the main controller 38 suppliesrecording data to the beam modulator 31 to start beam modulation (StepS2), and at the same time instructs the deflection controller 37 toperform deflection of the electron beam at a constant rate (Step S3). Inresponse to the constant rate deflection command, the deflectioncontroller 37 deflects the electron beam in the radial direction, namelythe inside peripheral direction (first deflection step). On the heightplane of the recording face of the master 4 the spot of the beam movesat a velocity equal to the feed velocity v of the stage 25. However,since the master 4 is moving in the same direction at the velocity v, asa result, the spot becomes a stationary state in the radial direction onthe master 4, and locates on the concentric circle that passes throughthe point A. That is, a pattern corresponding to the recording data issequentially drawn on the concentric circle that passes through thepoint A, through exposure in the direction indicated by arrows in FIG.3.

The main controller 38 then determines whether the recording location ofthe spot has traveled by one round and returned to the point A (StepS4). If the recording location has returned to the point A, thedeflection amount of the electron beam at this time point is 2δx, whichcorresponds to the first deflection amount. The deflection controller 37is instructed to perform high-speed deflection of the electron beam sothat the recording location is at the point B (Step S5). That is, thisis the second deflection step, in which the electron beam deflectionamount is returned to δx. This deflection amount corresponds to thesecond deflection amount. A determination id made as to whether therecording location of the spot is the location of the point B (Step S6).If the recording location is the location of the point B, recording datais supplied to the beam modulator 31 to start beam modulation (Step S7),while at the same time the deflection controller 37 is instructed toperform constant rate deflection of the electron beam (Step S8). Apattern corresponding to the same recording data, which is formed on theconcentric circle that passes through the points A, is drawn throughexposure onto the concentric circle that passes through the point B.

The main controller 38 determines whether the recording location of thespot has traveled by one round and returned to the point B (Step S9). Ifthe recording location has returned to the point B, the deflectionamount of the electron beam at this time point is 3Δx. The deflectioncontroller 37 is instructed to perform high-speed deflection of theelectron beam so that the recording location is at the point C (StepS10). That is, the deflection amount of the electron beam is 2δx. It isdetermined whether the recording location of the spot is the location ofthe point C (Step S11). If the recording location is the location of thepoint C, recording data is supplied to the beam modulator 31 to startbeam modulation (Step S12), while at the same time the deflectioncontroller 37 is instructed to perform constant rate deflection of theelectron beam (Step S13). A pattern corresponding to the same recordingdata, which is formed on the concentric circles that pass through thepoints A and B, is drawn through exposure onto the concentric circlethat passes through the point C.

The main controller 38 then determines whether the recording location ofthe spot has traveled by one round and returned to the point C (StepS14). If the recording location has returned to the point C, thedeflection amount of the electron beam at this point in time is 4δx. Thedeflection controller 37 is instructed to perform high-speed deflectionof the electron beam so that the recording location is now at the pointD (Step S15). Specifically, the deflection amount of the electron beamis 3δx. It is determined whether the recording location of the spot isthe location of the point D (Step S16). If the recording location is thelocation of the point D, recording data is supplied to the beammodulator 31 and beam modulation is initiated (Step S17), while at thesame time the deflection controller 37 is instructed to perform constantrate deflection of the electron beam (Step S18). A pattern correspondingto the same recording data, which is formed on the concentric circlesthat pass through the points A, B, and C, is drawn through exposure ontothe concentric circle that passes through the point D.

The main controller 38 determines whether the recording location of thespot has traveled by one round and returned to the point D (Step S19).If the recording location has returned to the point D, pattern drawingis completed for the recording data of one track. The deflection amountof the electron beam at this point in time is 5δx. The deflectioncontroller 37 is instructed to perform high-speed deflection of theelectron beam so that the recording location is at the point A of thenext track (Step S20). This corresponds to the third deflection step,and involves returning the deflection amount of the electron beamequivalent to the third deflection amount 5δx to zero. The operation ofabove steps S1 through S20 is repeated for the next track.

Consequently, the spot location in the radial direction moves over timeas shown in FIG. 5A, and the deflection amount of the electron beam onthe recording face changes as shown in FIG. 5B. FIG. 6 shows therelationship between the irradiation location and change in thedirection of deflection of the electron beam with respect to the master4. In FIG. 6, the electron beams shown by the solid lines depict thedeflection state at the start of recording of each concentric circle,while the electron beams shown by the broken lines depict the deflectionstate at the completion of recording of each concentric circle. From thedrawings it is understood that at the recording start point A, which isthe point in time of starting of drawing through exposure for one track,the deflection amount of the electron beam is zero; while at therecording end point D, which is the point in time of completion ofdrawing, the deflection amount of the electron beam is 5δx. Thedeflection amount of 5δx is reset to a deflection amount of zero throughhigh-speed deflection. The spot is situated at the recording start pointA for the subsequent second track. By repeating this operation for eachtrack, patterns can be drawn on each of the plurality of tracks withoutcarrying out a blanking operation equivalent to the movement amount ofthe stage between the concentric circles. Since the deflection amount ofthe electron beam during drawing of one track can be an amount less thanthe movement amount of the stage (the track pitch), it is possible tocarry out drawing within a short time, as well as possible to writeconcentric circles with high resolution and high accuracy throughutilization of a multiple exposure averaging effect.

In the preceding embodiment, one track is produced by drawing concentriccircles four times, but it would be acceptable to produce one track bydrawing concentric circles a number n of times other than four. In thiscase, as shown in FIG. 7, where track width is nδx and width of thelands between tracks is mδx, track pitch is (n+m)δx. The feed velocity vof the stage 25 is expressed as:

v=(V/2πR)×(n+m)δx/n=Vδx(n+m)/2nπR

where V denotes recording linear velocity and R denotes radius of therecording location. During drawing equivalent to one revolution of thespindle motor 22 from the recording start point A1 back to the startpoint A1, the deflection amount of the electron beam is (n+m)δx/n.Through high-speed deflection of the electron beam so as to change therecording location from the point A1 to the following point A2, thedeflection amount of the electron beam is reduced by δx, to mδx/m. Thesubsequent deflection amount of the electron beam is comparable, withthe spot location in the radial direction shifting over time as shown inFIG. 8A and with the deflection amount of the electron beam on therecording face changing over time as shown in FIG. 8B.

Because the stage movement velocity is proportional to the deflectionamount (n+m)δx/n, by setting m to a larger value compared to n, thestage can be moved faster, thus making it possible to shorten drawingtime. By shortening the write time, the system is less susceptible tothe effects of fluctuations of the electron beam, contributing toimproved recording accuracy.

In the preceding embodiments, at the point in time that the beam spot issituated at the recording start point A or A1 for each of the tracks,the deflection amount of the electron beam is zero; however, the beamcould have a deflection amount different from zero at the start point.

According to the present invention as set forth above, a plurality ofconcentric circular data patterns for forming one track are exposed. Inthe exposure of each of the concentric circular data patterns, duringeach exposure of the concentric circular data patterns corresponding tothe first through (n−1)-th rounds, the electron beam is deflected on thesurface of the original master in the direction of planar movement ofthe master by a first deflection amount per revolution of the master.When the exposure of each of the concentric circular data patternscorresponding to the first through (n−1)-th rounds is completed, theelectron beam is deflected by a second deflection amount on the surfaceof the master. Further, the exposure of the concentric circular datapattern corresponding to the n-th round is completed, the electron beamis deflected by a third deflection amount in the direction opposite tothe planar movement direction of the master such that the irradiationposition of the electron beam is located at the exposure start positionof the first concentric circle of the adjacent track. Thus, thedeflection amount of the electron beam is an amount less than themovement amount of the master in a predetermined radial direction duringone revolution, whereby it is possible to carry out drawing within ashorter time, as well as to expose data pattern tracks with highresolution and high accuracy through utilization of a multiple exposureaveraging effect.

The original master manufacturing method according to the presentinvention is suitable for data pattern lithography of a master forfabrication of substrates for magnetic disks such as hard disks.

1. An original master manufacturing method of irradiating an electronbeam on an original master having a resist layer on a surface to exposea concentric circular data pattern by n (n is an integer that is equalto or greater than 2) rounds per track at a predetermined distance, sothat a plurality of tracks having a predetermined track pitch are formedon the original master, the method comprising: a rotation driving stepof rotary-driving the original master at a constant linear velocity; amovement step of moving in a plane the original master in apredetermined radial direction at a constant velocity which is providedwith a predetermined amount of movement per round of the originalmaster; a first deflection step of deflecting the electron beam in theplanar movement direction of the original master by a first deflectionamount equal to the predetermined movement amount per round of theoriginal master on the surface of the original master during exposure ofthe concentric circular data patterns corresponding to first through(n−1)-th rounds of each of the plurality of tracks; a second deflectionstep of deflecting the electron beam in a direction opposite to theplanar movement direction of the original master by a second deflectionamount equal to the predetermined distance on the surface of theoriginal master, upon completion of the exposure of the concentriccircular data patterns corresponding to the first through (n−1)-throunds; and a third deflection step of deflecting the electron beam inthe direction opposite to the planar movement direction of the originalmaster by a third deflection amount on the surface of the originalmaster such that an irradiation position of the electron beam is locatedat an exposure start position on the concentric circle of a first roundof an adjacent track, upon completion of exposure of the concentriccircular data pattern corresponding to an n-th round of each of theplurality of tracks.
 2. The original master manufacturing methodaccording to claim 1, wherein when the predetermined distance is givenby δx (δx is a positive number), a land width between the tracks isgiven by mδx (m is an integer that is equal to or greater than 1), andthe track pitch is given by (n+m)δx, the predetermined movement amountand the first deflection amount are (n+m)δx/n, the second deflectionamount is δx, and the third deflection amount is (m+1)δx.
 3. Theoriginal master manufacturing method according to claim 1, wherein adeflection amount of the electron beam is zero at the exposure startlocation of the concentric circle corresponding to the first round ofeach of the plurality of tracks.
 4. The original master manufacturingmethod according to claim 1, wherein upon returning to the exposurestart location of each of the concentric circular data patternscorresponding to the first through (n−1)-th rounds, the electron beam isdeflected by high-speed deflection in the direction opposite to theplanar movement direction of the original master by the seconddeflection amount equal to the predetermined distance on the surface ofthe original master in the second deflection step.
 5. The originalmaster manufacturing method according to claim 1, wherein upon returningto the exposure start location of the concentric circular data patterncorresponding to the n-th round, the electron beam is deflected byhigh-speed deflection in the direction opposite to the planar movementdirection of the original master by the third deflection amount on thesurface of the original master in the third deflection step.
 6. Theoriginal master manufacturing method according to claim 1, wherein theexposure start location of each of the concentric circular data patternscorresponding to the first through n-th rounds is located in a sameradial direction of the original master.
 7. A computer-readable programfor executing an original master manufacturing method of irradiating anelectron beam on an original master having a resist layer on a surfaceto expose a concentric circular data pattern by n (n is an integer thatis equal to or greater than 2) rounds per track at a predetermineddistance, so that a plurality of tracks having a predetermined trackpitch are formed on the original master, comprising: a rotation drivingstep of rotary-driving the original master at a constant linearvelocity; a movement step of moving in a plane the original master in apredetermined radial direction at a constant velocity which is providedwith a predetermined amount of movement per round of the originalmaster; a first deflection step of deflecting the electron beam in theplanar movement direction of the original master by a first deflectionamount equal to the predetermined movement amount per round of theoriginal master on the surface of the original master during exposure ofthe concentric circular data patterns corresponding to first through(n−1)-th rounds of each of the plurality of tracks; a second deflectionstep of deflecting the electron beam in a direction opposite to theplanar movement direction of the original master by a second deflectionamount equal to the predetermined distance on the surface of theoriginal master, upon completion of the exposure of the concentriccircular data patterns corresponding to the first through (n−1)-throunds; and a third deflection step of deflecting the electron beam inthe direction opposite to the planar movement direction of the originalmaster by a third deflection amount on the surface of the originalmaster such that an irradiation position of the electron beam is locatedat an exposure start position on the concentric circle of a first roundof an adjacent track, upon completion of exposure of the concentriccircular data pattern corresponding to an n-th round of each of theplurality of tracks.
 8. An electron beam lithography system forirradiating an electron beam on an original master having a resist layeron a surface to expose a concentric circular data pattern by n (n is aninteger that is equal to or greater than 2) rounds per track at apredetermined distance, so that a plurality of tracks having apredetermined track pitch are formed on the original master, the systemcomprising: a rotation driving portion which rotary-drives the originalmaster at a constant linear velocity; a movement portion which moves ina plane the original master in a predetermined radial direction at aconstant velocity which is provided with a predetermined amount ofmovement per round of the original master; a first deflection portionwhich deflects the electron beam in the planar movement direction of theoriginal master by a first deflection amount equal to the predeterminedmovement amount per round of the original master on the surface of theoriginal master during exposure of the concentric circular data patternscorresponding to first through (n−1)-th rounds of each of the pluralityof tracks; a second deflection portion which deflects the electron beamin a direction opposite to the planar movement direction of the originalmaster by a second deflection amount equal to the predetermined distanceon the surface of the original master, upon completion of the exposureof the concentric circular data patterns corresponding to the firstthrough (n−1)-th rounds; and a third deflection portion which deflectsthe electron beam in the direction opposite to the planar movementdirection of the original master by a third deflection amount on thesurface of the original master such that an irradiation position of theelectron beam is located at an exposure start position on the concentriccircle of a first round of an adjacent track, upon completion ofexposure of the concentric circular data pattern corresponding to ann-th round of each of the plurality of tracks.
 9. The electron beamlithography system according to claim 8, wherein the first through thirddeflection portions each deflect the electron beam by a same high-speeddeflector.